NASA's Curiosity Rover Spots A Strange Ball On Mars

Is NASA's Mars Curiosity Rover getting swept away with Ryder Cup fever? The $2.5bn rover has just snapped a photo of what appears to be a perfectly round, golf ball-sized rock, which is not the sort of thing you would normally expect to find on the barren surface of Mars.

(Credit: NASA/JPL-Caltech)

According to the team behind Curiosity at NASA's Jet Propulsion Lab in California, this is not a sign of ancient alien sporting competition, it is instead a phenomenon known as 'concretion'. Concretion occurs when minerals form within the pores of sedimentary rock, which is prevalent in lake beds. When the rock is eroded, the more robust mineral formations - often taking on oddly perfect shapes - are left behind. As is becoming increasingly apparent, Mars was once a water-filled oasis, and it is believed that back then, Curiosity's current stomping ground (the Gale Crater) formed a large lake bed.

This is not the first time concretion has been witnessed on Mars, though. Back in 2004, NASA's Opportunity Rover observed what were described as blueberry-sized rock formations on the meridiani planum, which at the time formed one of the strongest signs yet that water had once been present on the planet's surface.

Curiosity's time on Mars has uncovered many weird and wonderful sights, and while you can certainly add this to the list, don't expect it to be the last. Up next on the menu for the Curiosity is the drilling and analysis of more rock samples around the base of the massive Aeolis Mons (Mount Sharp).